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Infectious Causes Impacting Reproduction

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Presentation on theme: "Infectious Causes Impacting Reproduction"— Presentation transcript:

1 Infectious Causes Impacting Reproduction


3 Fetal Mummification Fetus dies, uterus contracts, and fluid is resorbed  fetus becomes dry/firm Thickened uterus CL present on ovary No palpable cotyledons No membrane slip No fremitus in uterine artery Palpable mass in uterus

4 Fetal Mummification Most common at 4-6 months of gestation, but may go beyond gestation length Genetic (uncommon) – Jerseys, Guernseys, certain Holstein families Torsion of umbilical cord Infectious diseases that cause minimal inflammation: Campylobacter fetus BVDV Tx: PGF2a IM to lyse CL and expel fetus in 2-3 days +/- 2nd dose in 96 hrs if needed Manually remove with lube C-section

5 Fetal Maceration Fetal death with partial cervical dilation  uterine contamination  bacterial growth (great medium!) Any age of gestation CS: abdominal straining, foul fetid vulvar discharge, fever, anorexia, milk production +/- diarrhea Rectal: distended swollen uterus, gas crepetation in fetus Prognosis for future reproduction POOR - treatment not always successful, endometrial damage extensive Tx: Cervix dilated: fetus removed manually with LUBE and SLOW manipulation. Re-examine for 2nd fetus! Cervix closed: PGF2a +/- oxytocin (less successful than with mummies; may not be functional CL)

6 Abortion Severe maternal illness: Placentitis: Fetal origin:
Infectious diseases: high fever, inflammation (mastitis, pneumonia, virus…) Toxins: plants and chemicals (nitrates, moldy sweet clovers, fescue molds, lupines, gossypol in cottonseeds, and industrial pollutants…) Hypoxia (anemia, pneumonia…) Endotoxemia Placentitis: Hematogenous Ascending via cervix Fetal origin: Fetal stress → death

7 Abortion Mechanism: P4 and PGF2a  luteolysis + expulsion of fetus

8 Abortion Due to the degree of autolysis and edema of fetuses in utero after death but before expulsion, gross placental/fetal lesions are not usually diagnostically significant.

9 Abortion What tissues samples shall I send off ? FRESH, keep cool
Fetal membranes/aborted fetus – BEST! Fetal lung, liver, intestines, brain, kidneys… Maternal serum, urine, vaginal discharge… FRESH, keep cool Better too many than too few samples…

10 Abortion Protozoal Bacterial Trichomonas Brucella spp Neospora
Infectious Causes: Bacterial Brucella spp Listeriosis Leptospirosis Arcanobacterium pyogenes Vibriosis *Especially if abortion storm! Protozoal Trichomonas Neospora Viral IBR BVD Mycotic

11 Brucellosis “Contagious abortion”, “Bangs disease” Brucella abortus
ZOONOTIC – Undulent fever in humans (via milk) Eradication program  ~rare in US herds, but still in free-ranging bison/elk Highly infectious – spread via aborted fetus, placenta, vaginal discharge, milk, or semen from infected bull Lesions – chorionic placentitis, Moroccan leather appearance, focal necrosis of cotyledons, thickened intercotyledonary areas with yellow exudate

12 Brucellosis Abortion usually between 5th-8th month of gestation
Also frequently causes retained placenta, weak calves and infertility Dx: serology/culture of fetal abomasal fluid, lung, and liver, placenta, uterine fluid, milk, serum, seminal plasma Prevention/Control: Official calfhood vaccination RB-51 vaccine (“bangs” vaccine) + Official USDA Brucellosis eartag + official ear tattoo Calves 4-10 months of age By state and federal brucellosis program personnel and USDA accredited veterinarians

13 Listeriosis “Circling Disease” Listeria Monocytogenes ZOONOTIC
Widespread in environment; transmission via ingestion of poorly fermented silage Fever, weight loss, endometritis, encephalitis Lesions: suppurative placentitis, small white foci on fetal liver and cotyledons, fibrin in fetal body cavity

14 Listeriosis Abortion usually during 3rd trimester
Sporadic or abortion storm Retained fetal membranes Control: stop feeding spoiled material, isolate aborting cows Broad Spectrum Antibiotics  milk withdrawal due to milk residues! NO vaccine in US

15 Leptospirosis Leptospira interrogans serovars hardjo & pomona
Transmission via infected urine, placental fluids, milk, or contaminated environment/water source Abortion from 4 months to term +/- yellow MM, blood tinged urine and milk Weak calves or infertility is also common Dx: Culture - organisms in fetal kidney Tx: Vaccinate annually

16 Arcanobacterium pyogenes
Abortion at any stage of pregnancy Normal inhabitant in nasopharynx of many cows, also in abscesses, NOT in fetuses or fetal membranes = always significant! Bloodstream  endometritis & placentitis (diffuse with a reddish brown to brown color) Fetus: autolyzed, with fibrinous pericarditis, pleuritis, or peritonitis possible, as well as bronchopneumonia Dx: culture from placenta or abomasal contents NO effective bacterin available

17 Arcanobacterium pyogenes
*Important cause of pyometra post-calving in DAIRY cows! Diagnosed at pre-breeding check (~ 40 d post calving) Occurs when cow ovulates in face of A. pyogenes in uterus  pyometra Usually uterine contaminates are expelled from uterus during normal involution process Pre-disposing factors: dystocia, RFM, metritis

18 Vibriosis Campylobacter fetus subsp venerealis
Bulls are asymptomatic carriers, permanent carries when > 4 yrs Venereal transmission  organism attacks conceptus  early embryonic death (occasional abortions ~ 4-7 months of gestation) Cows develop immunity and conceive, and maintain the disease in the herd (carriers) Dx: Blood agar culture of preputial smegma, fetal abomasal contents, vaginal/cervical mucous Tx: ID and cull carriers, topical antibiotic ointment Control/Prevention: AI, prevent re-infection, blood culture all non-virgin bulls 6-8 weeks before breeding season, VACCINATE cows and bulls

19 Trichomoniasis Trichomonas foetus
Bulls are asymptomatic permanent carriers Venereal transmission  organism attacks conceptus Cows develop immunity and conceive (carriers) *Important cause of pyometra post-breeding in BEEF cows CS: infertility, pyometra, abortion Dx: microscopic isolation of organism (preputial smegma or vaginal/cervical mucous) with Diamond’s medium (Klaas modification) Control/Prevention: AI, use of virgin bulls NO vaccine available

20 Neospora Neospora caninum
Cycles between canids and ruminants – oral or vertical transmission Mid-gestation abortion (~4-6 months), pre-mature calf, birth of impaired calf, or normal calf Brain hemorrhage, myocarditis

21 Oocysts ingested while grazing
 Sporozoites released, enter SI  reticulo-endothelial system Tachyzoites = invade different tissues, placenta  fetus in pregnant animals Bradyzoites = dormant, within tissue cysts (found mainly in neural tissue) In future pregnancies, bradyzoites  tachyzoites  invade the fetus via the placenta

22 Infectious Bovine Rhinotracheitis (IBR)
Acute, contagious Bovine Herpes Virus Infertility, respiratory infections, conjunctivitis, abortion storm usually > 5 months gestation RFM, placental edema/vasculitis Fetus: red serous body fluid, white foci on liver/lungs Tx: Vaccinate annually “red nose”

23 Infectious Pustular Vulvovaginitis
Also a Bovine Herpes Virus Venereal/mechanical spread Genital pustules (balanoposthitis) Spontaneous recovery

24 Bovine Viral Diarrhea Virus (BVD)
Affects the digestive, respiratory, immune, nervous and reproductive systems BVD Type I and Type II, each with: Cytopathic (CPE) strains  cellular vacuolation and cell death Non-cytopathic (non-CPE) strains  no visible cytopathic change in cell cultures

25 Bovine Viral Diarrhea Virus (BVD)
BVD infection in-utero: Slows fetal growth  lower birth weight, bone growth Abortion (at any trimester) Early embryonic death Stillbirth Congenital Birth Defects (eye, thymus, brain) Arthrogryposis PI Calves (immunotolerant and persistently infected shedders) Normal calf born with antibodies to the BVD virus cerebellar hypoplasia

26 Bovine Viral Diarrhea Virus (BVD)
Results of fetal infection with BVDV Outcome Gestational age at time of in utero infection. days > 180 days Normal, antibody negative calf X Abortion Early embryonic death, resorption Mummification Stillbirth Congenital defects, antibody negative Congenital defects, antibody positive Persistently infected, "normal" calf +/- Normal, antibody positive calf

27 Bovine Viral Diarrhea Virus (BVD)
Mucusal disease: PI calf (infected in-utero from d of gestation with non-CPE strain, seem normal, but have no immunity to the virus) + encounters CPE strain after birth (vulnerable to severe effects of the CPE cell-killing strain) ~6 months – 2 yrs old High mortality

28 Bovine Viral Diarrhea Virus (BVD)
BVD infection after birth: Usually 6 months to 2 yrs of age CS: vary depending on the virulence of the strain Viremic  develop antibodies  clear virus within 7-10 days Subclinical (estimated 70-90% of BVDV infections) Mild elevation in body temp, drop in milk production Clinical = Acute BVD Depression, fever, inappetence, nasal discharge, transient leukopenia, thrombocytopenia, petechial hemorrhages, diarrhea, high morbidity, low mortality Eliminate Carriers = CULL! VACCINATE before breeding

29 Mycotic Abortion Aspergillus, Absidia, Mucor, Rhizopus, Candida
More in WINTER when cattle housed/fed inside Injury to respiratory/GIT  hematogenous  uterus  severe necrotic placentitis Thick, leathery cotyledons + intercotyledonary placenta Abortions in 3rd trimester Head and neck lesions on fetus

30 “Given the low diagnostic success rate, the high cost of laboratory work, and the low profit margin in both the beef and dairy industries, veterinarians should not attempt to make an etiologic diagnosis in every abortion. Instead, veterinarians should become concerned if fetal loss is >3-5% per year or per month.” ~ The Merck Veterinary Manual

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